This research was conducted in 2006 in the Experimental Station of the Department of Genetics and Horticultural Plant Breeding in Felin near Lublin. It included 7 cultivars of strawberry (‘Pastel’, ‘Salut’, ‘Teresa’, ‘Jota’, ‘Paula’, ‘Senga Sengana’, ‘Plena’) and two selected clones: 2395 and 3995 that belonged to the Department. Analysis of pollen fertility was carried out on the basis of materials collected on fi ve occasions: on May 17 (at the beginning of fl orescence), May 20 and May 24 (the peak of fl orescence) and on June 2 and June 13 (the end of fl orescence). Smear preparations stained with 2% acetocarmin and glycerin solution (1:1) were used to test pollen viability. The highest percent of viable pollen in 2006 was in cultivar ‘Jota’ (70.88%). The lowest viability had pollen of ‘Teresa’ cultivar (33.83%). The average content of viable pollen grains was the lowest on May 20 (36.79%). The highest pollen fertility was noted on June 2 (62.15%), the percent of fertile pollen on a similar level was observed on May 17 and 24 and June13. The cultivar ‘Jota’ was characterized by an increased level of pollen fertility that was quite high during the whole period of fl orescence. The number of seeds has a great infl uence on the proper development of spurious strawberry fruit. The mass of seeds from a single fruit has a great infl uence on the mass of fruits in both large and small fruit categories. Pollen viability affected the mass of seeds on big fruits (r = 0.444), but there is no clear direct relationship between pollen fertility and mass of strawberry fruit(r = -0.193 and r = -0.052).
Poor seed set is a limiting factor in alfalfa breeding, as it slows the selection response. One strategy used to overcome this problem is to search for mutations of inflorescence morphology. Long-peduncle (lp), branched-raceme (br) and top-flowering (tf) inflorescence mutations increase the number of flowers per inflorescence, but they do not improve seed set per flower. Here we assessed pollen tube growth in styles of those inflorescence mutants and we observed embryo and endosperm development in seeds 1 to 16 days after pollination (DAP). The number of pollen tubes penetrating the style and the ovary was similar in all tested mutants and in the reference cultivar Radius. At 2 DAP, fertilized ovules were 2.7–3.9 times less numerous in certain inflorescence mutants than in the short-raceme cv. Radius. Ovule degeneration progressed at 2–4 DAP in all analyzed plants. Most ovules were not properly developed in the control cultivar (62%), nor in the forms with mutated inflorescence morphology (69–86%). The number of seeds per pod was lowest in the tf form despite its having the highest number of ovules per ovary. It appears that the number of ovules per pistil is not a crucial factor in seed set in alfalfa when fertilization efficiency is very low. Both poor fertilization and gradual ovule degeneration were factors causing poor seed set in the investigated alfalfa genotypes.
Pollen viability of 11 strawberry cultivars differing of photoperiodic sensitivity was investigated. During whole flowering period, average content of fertile pollen of everbearing fruit cultivars (‘Ostara’, ‘Geneva’, ‘Mara des Bois’, ‘Rapella’) amounted 28.5% and remained at the same level, whereas day-neutral cultivars (‘Selva’, ‘Tango’, ‘Evita’, ‘Irvine’) in third decade of June and July decreased at 35.2% in comparison to May level. Radiolographic analysis of plump seeds of 5 strawberry cultivars confirmed close relationship between pollen fertility and the plump of seeds.
In Poland, like in other parts of Central Europe, dry grasslands significantly contribute to the biodiversity of both fauna and flora. Anthropogenic pressure impair many species of xerothermic habitats, and several populations face an increased risk of extinction. The goal of the study was to define factors that may affect the size of wild populations of Anemone sylvestris L., a protected species in Poland, with both a short- and long-term perspective, and to examine the influence of vegetation changes on the density, the abundance of flowering and male function (pollen production, pollen viability), as well as seed set. In situ observations were performed in 2005-2006 and 2011-2012 in three populations located on the Lublin Upland, SE Poland. The reduction in population density and A. sylvestris blooming was exacerbated by the expansion of the shrubs, but not by Brachypodium pinnatum. Male characteristics of A. sylvestris, i.e. pollen amount per multi-staminate flowers or pollen viability appeared to decrease under pressure of shrub competition. Populations with limitation of male function had impaired degree of seed set. Various consequences for the functioning of populations within a metapopulation system can be expected due to substantial qualitative and quantitative disorders in pollen traits. It is crucial that successful recovery programs for A. sylvestris primary should aim to conserve and manage the habitat.